This invention relates to a process for the conversion of CO and hydrogen to aromatic hydrocarbon mixtures which are useful as fuels in automobile engines and the like. More particularly, this invention relates to a one-step conversion of CO and hydrogen to said aromatics in the presence of a novel catalyst composition comprising a mixture of a promoted iron catalyst defined hereinbelow and a mole sieve also defined below.
Belgian Pat. No. 828,228 (together with corresponding British Pat. No. 1,495,794 and French Pat. No. 2,268,771) describes a process for the conversion of synthesis gas to a liquid product containing a high proportion of C.sub.5.sup.+ olefins, isoparaffins and/or aromatics, using a CO-reduction catalyst in combination with a crystalline aluminosilicate (zeolite). This patent, however, requires that said zeolite have (1) an SiO.sub.2 /Al.sub.2 O.sub.3 ratio of greater than 12; and, as defined by said patent, (2) a "constraint index" of 1 to 12; and (3) a "crystal framework density" of not less than 1.6 grams/cc.
By contrast, the present invention employs as the zeolite component a Y zeolite having an SiO.sub.2 /Al.sub.2 O.sub.3 ratio of no greater than 6. Moreover, as the Belgian patent itself teaches, Y zeolites do not fall within its defined ranges of the constraint index and crustal framework density.
U.S. Pat. No. 3,972,958 and Storch et al, Fischer-Tropsch and Related Synthesis, John Wiley, New York, 1951, pp. 428-434 also bear on the subject of this invention.